Dec. 16, 2009
Ruth Dasso Marlaire
Ames Research Center, Moffett Field, Calif.
650.604.4709
ruth.marlaire@nasa.gov
RELEASE: 09-155AR
NASA CALCULATES A CARBON BUDGET FOR THE STATE OF CALIFORNIA
MOFFETT FIELD, Calif. -- While world organizations struggle to find a
benchmark and tracking standards for greenhouse gas (GHG) emissions,
NASA has been supporting California’s new carbon emissions inventory
report, using its satellite imaging data and computer models of the
state’s natural ecosystems.
Researchers report that in 2004, the state’s natural ecosystems
absorbed as much carbon dioxide from the atmosphere as fossil fuel
carbons emitted into the atmosphere. They also discovered that during
periods of above normal rainfall, ecosystems trapped significant
amounts of carbon dioxide from the atmosphere in forests and soils.
For these reasons, researchers suggest the ecosystems should be more
extensively protected and conserved, and their emissions be monitored
as closely as fossil fuel sources of GHG emissions. The results,
based largely on a computer model called the NASA-Carnegie Ames
Stanford Approach (CASA), will be presented this morning at the 2009
American Geophysical Union Fall meeting in San Francisco.
"One way to facilitate emissions reductions is by using regional and
national carbon budgets," explained Christopher Potter, senior
research scientist at NASA Ames Research Center, Moffett Field,
Calif., and author of this study. "California’s growing population
and demand for all forms of energy make it essential to maintain an
accurate and complete accounting of the state’s greenhouse emissions
inventory," Potter added.
California’s population is more than 10 percent of the total
population in the United States, and produces 13 percent of the U.S.
gross domestic product, according to 2000 U.S. Census Bureau data.
Because of its large population, the state also contributes
significantly to global GHG emissions. If California was a country,
it would rank among the top 20 national GHG emitters worldwide.
The carbon budget of a region is determined by the amounts of carbon
dioxide and methane gases absorbed or released by “green” vegetative
ground cover, as observed by NASA satellites. These fluctuations are
important to quantify, because they originate from both natural and
anthropogenic processes.
In California, the main sources of carbon dioxide emissions are energy
consumption in commercial, residential, industrial, and
transportation sectors, production of cement and lime, and waste
treatment. The main sources of methane emission are derived from
landfills and agricultural (principally livestock-based) systems.
Scientists believe that California’s carbon budget is of special
interest because the state may represent a U.S. national carbon
budget; both have diversified lands, similar consumption of natural
resources, and urban lifestyles. Other similarities include a mix of
fossil fuel emissions, alternative energy sources, and ecosystem
sinks.
Each year, California is required by law to compile a new carbon
emission inventory, which is conducted by the California Energy
Commission and California’s Air Resources Board. To refine the
state’s emission inventory, NASA was asked to provide NASA satellite
imaging data and carbon models. To locate the largest ecosystem
sources and carbon sinks in California, scientists used the Moderate
Resolution Imaging Spectroradiometer (MODIS) aboard the NASA Terra
satellite. The vegetation “greenness” data from the MODIS sensor was
directly downloaded into the CASA ecosystem simulation model.
Scientists used the data to estimate monthly variations in the
accumulated biomass of wood and other plant materials, such as the
accumulated dead leaf biomass transferred into soil carbon pools.
Inventory data from the California Energy Commission also was used to
model the carbon dioxide emissions from fossil fuel combustion and
greenhouse gas emissions from agricultural lands throughout the
state.
This project was funded by NASA as part of a long-term research
program dedicated to understanding how human-induced and natural
changes affect our global environment.
For more information about NASA and agency programs on the Web, visit:
http://www.nasa.gov/home
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